Liming materials. Determination of the lime requirement in soil. Ammonium acetate buffer method pH 5,5

2019 ◽  
Keyword(s):  
Ammonium Acetate ◽  
Acetate Buffer ◽  
Ammonium Acetate Buffer ◽  
Soil Ammonium

scholarly journals DETERMINATION OF Cu(II) CONCENTRATION IN AQUEOUS MEDIUM USING INVERSION ELECTROCHEMICAL METHOD

2019 ◽  
Vol 85 (9) ◽  
pp. 58-64
Author(s):  
Vera Vorobets ◽  
Gennadii Kolbasov ◽  
Sergii Fomanyuk ◽  
Nataliia Smirnova ◽  
Oksana Linnik
Keyword(s):  
Formic Acid ◽  
Ammonium Acetate ◽  
Copper Ions ◽  
Stripping Voltammetry ◽  
Acetate Buffer ◽  
Background Solution ◽  
Ammonium Acetate Buffer ◽  
Photoelectrochemical Method ◽  
Determination Of Copper

Electrode materials based on titanium dioxide modified with zinc ions and gold nanoparticles, synthesized by sol-gel method, were used to determine the concentration of Cu (II) in liquids by stripping voltammetry method. Determination of Cu (II) was done using background solutions based on 0.4 M formic acid and ammonium acetate buffer (pH = 7.5) using the standard addition method with a potential scanning speed of 50 mV•s-1. The solution was stirred during the preliminary electrolysis at a potential of -1400 mV (vs silver-chloride reference electrode) for 120 seconds and then the potential was scanned from -1200 mV to + 200 mV. It is shown that the background solution based on ammonium acetate buffer provides a higher sensitivity and a good selectivity of peaks for the determination of copper compared to the background solution based on formic acid. Determined that value of the analytical signal of copper in the studied model solutions based on ammonium acetate and formic acid is proportional to the concentration of copper ions in the solution. To increase the selectivity of stripping voltammetry method in determining copper concentrations in solutions, an inversion spectral photoelectrochemical method was proposed, the essence of which is preliminary electroconcentration of the elements under investigation in the cathode potential region and subsequent measurement of the spectral photoelectrochemical characteristics of electroconcentration products. It has been found that in solutions of 1M ammonium acetate containing Cu2+ ions, the cathodic polarization of TiO2-based photoelectrode leads to the appearance of a cathode photocurrent and the values of photocurrent quantum yield increase with increasing content of copper ions in the solution. The spectral sensitivity of the surface layer corresponds to the absorption spectrum of Cu2O. The sensitivity of stripping voltammetry method to copper Cu (II) using the materials studied was 0.3 mg•l-1. It is shown that the inversion photoelectrochemical method is promising in the selective determination of copper concentration in liquids.

scholarly journals Sequential Extraction of Potentially Toxic Metals: Alteration of Method for Cu-Ni Polluted Peat Soil of Industrial Barren

Toxics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 39
Author(s):  
Marina V. Slukovskaya ◽  
Irina P. Kremenetskaya ◽  
Svetlana V. Drogobuzhskaya ◽  
Andrey I. Novikov
Keyword(s):  
Ammonium Acetate ◽  
Peat Soil ◽  
Soil Treatment ◽  
Water Soluble ◽  
Acetate Buffer ◽  
Peat Soils ◽  
Ammonium Acetate Buffer ◽  
Fraction Composition ◽  
Metal Fraction

An evaluation of fraction composition and transformation of metal compounds emitted by metal ore processing enterprises and accumulated in soils is crucial for assessing the environmental risks of pollution and ecosystem benefit of remediation. The aim of this study was to develop a suitable sequential fractional procedure for metal pollutants for the peat soils matrix in the impact zone of a Cu-Ni smelter. Three experiment series were performed: (a) the study of the effect of ammonium acetate buffer pH in the range of 3.7–7.8 on the soil metal extraction; (b) the study of the effect of additional volume and frequency of soil treatment with solutions on the content of water-soluble, ammonium acetate extractable, and 0.1 N HNO3 extractable fractions; and, (c) the determination of the metal fraction composition in the modified technique. Soil treatment with ammonium acetate buffer with a pH range of 4.5–5.5 was the most appropriate for the determination of mobile compounds of Cu and other metals in highly polluted peat soil. Triple soil treatment with water and ammonium acetate is necessary for the complete extraction of the water-soluble and exchangeable fractions, respectively. Additionally, we propose a procedure of full extraction of the exchangeable metal fraction from peat soils while using single treatment with 0.1 N HNO3. This scheme allows evaluating geochemical mobility of metals and current environmental harm of polluted soils with a high content of organic matter.

scholarly journals DETERMINATION OF CU(II) CONCENTRATION IN AQUEOUS MEDIUM USING INVERSION ELECTROCHEMICAL METHOD

2019 ◽  
Vol 85 (7) ◽  
pp. 24-30
Author(s):  
Vera Vorobets ◽  
Gennadii Kolbasov ◽  
Sergii Fomanyuk ◽  
Nataliia Smirnova ◽  
Oksana Linnik
Keyword(s):  
Formic Acid ◽  
Ammonium Acetate ◽  
Copper Ions ◽  
Stripping Voltammetry ◽  
Acetate Buffer ◽  
Background Solution ◽  
Ammonium Acetate Buffer ◽  
Photoelectrochemical Method ◽  
Determination Of Copper

Electrode materials based on titanium dioxide modified with zinc ions and gold nanoparticles, synthesized by sol-gel method, were used to determine the concentration of Cu (II) in liquids by stripping voltammetry method. Determination of Cu (II) was done using background solutions based on 0.4 M formic acid and ammonium acetate buffer (pH = 7.5) using the standard addition method with a potential scanning speed of 50 mV•s-1. The solution was stirred during the preliminary electrolysis at a potential of -1400 mV (vs silver-chloride reference electrode) for 120 seconds and then the potential was scanned from -1200 mV to + 200 mV. It is shown that the background solution based on ammonium acetate buffer provides a higher sensitivity and a good selectivity of peaks for the determination of copper compared to the background solution based on formic acid. Determined that value of the analytical signal of copper in the studied model solutions based on ammonium acetate and formic acid is proportional to the concentration of copper ions in the solution. To increase the selectivity of stripping voltammetry method in determining copper concentrations in solutions, an inversion spectral photoelectrochemical method was proposed, the essence of which is preliminary electroconcentration of the elements under investigation in the cathode potential region and subsequent measurement of the spectral photoelectrochemical characteristics of electroconcentration products. It has been found that in solutions of 1M ammonium acetate containing Cu2+ ions, the cathodic polarization of TiO2-based photoelectrode leads to the appearance of a cathode photocurrent and the values of photocurrent quantum yield increase with increasing content of copper ions in the solution. The spectral sensitivity of the surface layer corresponds to the absorption spectrum of Cu2O. The sensitivity of stripping voltammetry method to copper Cu (II) using the materials studied was 0.3 mg•l-1. It is shown that the inversion photoelectrochemical method is promising in the selective determination of copper concentration in liquids.

LC–MS/MS Determination of Apigenin in Rat Plasma and Application to Pharmacokinetic Study

2020 ◽  
Vol 21 ◽  
Author(s):  
Shixing Zhu ◽  
Jiayuan Zhang ◽  
Zhihua Lv ◽  
Mingming Yu
Keyword(s):  
Formic Acid ◽  
Pharmacokinetic Study ◽  
Ammonium Acetate ◽  
Rat Plasma ◽  
Biological Properties ◽  
Plasma Samples ◽  
Supply Rate ◽  
Natural Plant ◽  
Ammonium Acetate Buffer

Background: Apigenin, a natural plant flavone, has been shown to possess a variety of biological properties. Objective: In this report, a highly selective and sensitive LC-MS/MS method was developed and validated for the determination of apigenin in rat plasma. Methods: Analysts were separated on the HSS T3 column (1.8 μm 2.1×100 mm) using acetonitrile and 0.1% formic acid in 2 mM ammonium acetate buffer at a supply rate of 0.200 mL/min as eluent in gradient model. Results: Plasma samples were treated by protein precipitation using acetonitrile for the recovery ranging from 86.5% to 90.1% for apigenin. The calibration curves followed linearity in the concentration range of 0.50-500 ng/mL. The inter-day and intra-day precisions at different QC levels within 13.1% and the accuracies ranged from -10.6% to 8.6%. Conclusion: The assay has been successfully applied to the pharmacokinetic study of apigenin in rats.

Polarographic Determination of Zinc in Compounded Rubber

1950 ◽  
Vol 23 (4) ◽  
pp. 975-980
Author(s):  
F. C. J. Poulton ◽  
L. Tarrant
Keyword(s):  
Zinc Oxide ◽  
Ammonium Acetate ◽  
Potassium Thiocyanate ◽  
Acetate Buffer Solution ◽  
Acid Electrolyte ◽  
Buffer Solution ◽  
Ammonium Acetate Buffer ◽  
Ammonium Acetate Buffer Solution ◽  
Gravimetric Procedure

Abstract Reasons are advanced for the unsatisfactory nature of some of the older methods for the determination of very small amounts of zinc in compounded rubber, particularly in latex mixings. The polarographic technique offers a possible solution, but most of the commoner electrolytes for the electroreduction of this metal are alkaline, and give rise to similar errors as are met in the gravimetric procedure. The development of a suitable acid electrolyte was therefore undertaken, and ways of dealing with likely interferences were examined. The electroltye finally recommended is a potassium thiocyanate-ammonium acetate buffer solution; iron, when present, is reduced to the ferrous condition by potassium iodide. The method was used to determine zinc oxide in a series of mixings of known composition ranging from 0.8 to 40 per cent. In all except the highest proportions of zinc oxide, the figures obtained agree well with the theoretical.

scholarly journals CENTRAL COMPOSITE DESIGN APPLIED IN HPLC OPTIMIZATION FOR ANALYSIS OF TARTRAZINE AND AURAMINE O IN POWDER DRINKS

2019 ◽  
pp. 211-215
Author(s):  
ANNISA DYAH LESTARI ◽  
Abdul Rohman ◽  
SUDIBYO MARTONO
Keyword(s):  
Central Composite Design ◽  
Flow Rate ◽  
Retention Time ◽  
Mobile Phase ◽  
Ammonium Acetate ◽  
Acetate Buffer ◽  
Ammonium Acetate Buffer ◽  
Acetate Concentration ◽  
Rp Hplc ◽  
Central Composite

Objective: This study was intended to optimize reversed-phase high-performance liquid chromatography (RP-HPLC) method for the determination of Tartrazine (TAR) and Auramin O (AUO) in powder drinks using experimental design of central composite design (CCD) approach. Methods: TAR and AUO in powder drink product has same properties, therefore both analytes were analysed using C18 column (XBridge Shield RP 18 250 mm x 4.6 mm i.d., 5 µm) using Shimadzu LC 20AD chromatograph equipped with photo-diode array (PDA) detector at 300-650 nm. Some factors responsible for RP-HPLC separation of TAR and AUO including the concentration of buffer, the ratio of mobile phase and flow rate were optimized using CCD. The responses evaluated were peak area, retention time, and tailing factor. The mobile phase used was acetonitrile and ammonium acetate buffer, and acetonitrile composition was optimized at 84-86% for separation of TAR and AUO, delivered at a flow rate of 0.8–1.2 ml/min, using ammonium acetate buffer at 19-21 mmol. Results: CCD showed that separation of TAR and AUO was influenced by flow rate, the ratio of acetonitrile and ammonium acetate concentration. These factors affected significantly to retention time, peak area, and tailing factor. The optimal condition obtained based on CCD was flow rate of 1.2 ml/min, the ratio of acetonitrile 86%, and ammonium acetate concentration of 19 mmol. Conclusion: CCD can be used to get optimum condition for analysis of TAR and AUO in powder drink product.

TLC-Densitometric and RP-HPLC Methods for Simultaneous Determination of Dexamethasone and Chlorpheniramine Maleate in the Presence of Methylparaben and Propylparaben

2017 ◽  
Vol 100 (1) ◽  
pp. 51-58
Author(s):  
Nehal F Farid ◽  
Ibrahim A Naguib ◽  
Radwa S Moatamed ◽  
Mohamed R El Ghobashy
Keyword(s):  
Particle Size ◽  
Quantitative Determination ◽  
Mobile Phase ◽  
Ammonium Acetate ◽  
Reversed Phase ◽  
Reversed Phase Hplc ◽  
Chlorpheniramine Maleate ◽  
Ammonium Acetate Buffer ◽  
Rp Hplc

Abstract Validated simple, sensitive, and highly selective methods are applied for the quantitative determination ofdexamethasone and chlorpheniramine maleate in the presence of their reported preservatives (methylparaben and propylparaben), whether in pure forms or in pharmaceutical formulation. TLC is the first method, in which dexamethasone, chlorpheniramine maleate, methylparaben, and propylparaben are separated on silica gel TLC F254 plates using hexane–acetone–ammonia (5.5 + 4.5 + 0.5, v/v/v) as the developing phase. Separated bands are scanned at 254 nm over a concentration range of 0.1–1.7 and 0.4–2.8 μg/band, with mean ± SD recoveries of 99.12 ± 0.964 and 100.14 ± 0.962%, for dexamethasone and chlorpheniramine maleate, respectively. Reversed-phase HPLC is the second method, in which a mixture of dexamethasone and chlorpheniramine maleate, methylparaben, and propylparaben is separated on a reversed-phase silica C18 (5 μm particle size, 250 mm, 4.6 mm id) column using 0.1 M ammonium acetate buffer–acetonitrile (60 + 40, v/v, pH 3) as the mobile phase. The drugs were detected at 220 nm over a concentration range of 5–50 μg/mL, 2–90 μg/mL, 4–100 μg/mL, and 7–50μg/mL, with mean ± SD recoveries of 100.85 ± 0.905, 99.67 ± 1.281, 100.20 ± 0.906, and 99.81 ± 0.954%, for dexamethasone, chlorpheniramine maleate, methylparaben paraben, and propylparaben, respectively. The advantages of the suggested methods over previously reported methods are the ability to detect lower concentrations of the main drugs and to show better resolution of interfering preservatives; hence, these methods could be more reliable for routine QC analyses.

Determination of Total Fluoride and/or Fluosilicic Acid Concentration by Specific Fluoride Ion Electrode Potentiometry

1970 ◽  
Vol 53 (3) ◽  
pp. 447-450
Author(s):  
Donald E Jordan
Keyword(s):  
Ionic Strength ◽  
Hydrofluoric Acid ◽  
Ammonium Acetate ◽  
Fluoride Ion ◽  
Selective Electrode ◽  
Ammonium Acetate Buffer ◽  
Hydrous Oxides ◽  
Fluosilicic Acid ◽  
Fluoride Ion Selective Electrode

Abstract A method is presented to determine total fluoride and/or fluosilicic acid concentrations directly, using the fluoride ion selective electrode. Samples can be analyzed at 20–30/hr with excellent precision; results are equivalent to those obtained with the AWWA standard t e s t procedure No. B 703–60. Hydrofluoric acid, if present in the fluosilicic acid samples, interferes in the calculation for H2SiF6 concentration but not for total fluoride present. Specifically, the fluoride ion is freed from fluosilicate a t pH 8.4–10.0; in addition, iron and aluminum hydrous oxides are formed at this pH. Then the solution is buffered to pH 5.7–5.9 at a fixed ionic strength with ammonium acetate buffer and the total fluoride is determined from a prepared calibration curve or computer program.

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